Iranian media say Iran has started its fourth mass trial for detainees with charges related to the unrest that followed the June 12 re-election of President Mahmoud Ahmadinejad.

The reports do not say how many protesters are on trial Tuesday in a Tehran revolutionary court. Several leading reformists are among the defendants, including Iran's former Deputy Interior Minister Mostafa Tajzadeh, former Deputy Foreign Minister Mohsen Aminzadeh and a former government spokesman Abdollah Ramezanzadeh.

Iran put 28 more detainees on trial earlier this month. Iran has used mass trials to prosecute more than 130 people since the election. Those on trial include high-ranking politicians, a French teacher, and Iranian staff of the British and French embassies.

Iranian opposition leader Mehdi Karroubi met with lawmakers Monday, where he discussed allegations that protesters detained after the disputed presidential election were subjected to rape and torture.

Karroubi told a panel charged with investigating the claims that he knew of four victims who are willing to testify but need assurances they will be protected.

Karroubi also posted a victim's testimony on his Web site, in which the victim says he was raped and nearly beaten to death while detained. The victim says when he tried to lodge a complaint, judiciary officials accused him of being bribed by Karroubi to come forward.

The opposition leader's allegations of detainee abuse have angered the country's hardliners, and Iran's parliament speaker rejected the claims as "baseless."

In June, Mr. Ahmadinejad won a second four-year term in a disputed election that opposition leaders say was rigged.